An operating system is the most important and major program
that runs on a system (computer). Every computer system must have an operating system
in order to run different programs. The operating system is collection of
software’s which manages various computer hardware resources. It additionally
provides common services to different computer programs.

An operating system performs several tasks such as:

Recognize
input from a keyboard

Send
output to a display screen (monitor)

Keep
track of files as well as directories on a disk

Control various peripheral devices like hard drive, printer,
video or sound card etc

A figure named as “Operating System & its Interfaces”
shows the above basic concept in a clear way:

Figure
1: “Operating System & its Interfaces”

An operating system generally
acts as an “ interaction” between computer user and computer hardware. The most
observable feature of an operating-system is its interface. The operating
system basically provides an environment where users can execute different
programs.

As soon as a user turn-on or boot
a computer, the operating system is loaded into memory automatically. The term
booting basically refers to the complete process of loading any operating
system into a computer’s memory. This process is usually done through a program
(commonly known as boot-strap loader) which is permanently stored in a
computer’s electronic circuitry (generally on a ROM-chip).

Types
of Operating System

1. Graphical User Interface (GUI) Operating-System

A GUI operating-system basically provides a
graphical-user-interface to its users in order to communicate with
system/computer. In this interface, the icons, menus or graphical objects are
being used for issuing commands. The users of GUI operating systems don’t need
to memorize different commands while interacting with computer. The examples of
GUI operating-system include:

Windows (The windows (operating
system) are very popular among all others).

Linux etc.

2. Command Line Operating-System

A command line operating-system basically provides a
command-prompt in order to type different commands. The users use these
commands while their interaction with computer. The users of command line
operating systems need to memorize different commands for performing various
tasks. The examples of command line operating-system include:

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